(1) There is a unused config brighterFatterKernelFile in the IsrTask. It probably needs to be removed as Butler is used to retrieve the file now. Having a line like config.processCcd.isr.brighterFatterKernelFile='' in the config file is confusing while the brighter fatter kernel is read fine.
(2) The butler dataset type of the brighter fatter kernel file is inconsistent in ip_isr and obs_subaru. ip_isr wants brighterFatterKernel, while obs_subaru and obs_base want bfKernel.
It seems the brighter fatter correction has only been tested/used for subaru so far?